1. Field of the Invention
The present invention relates to latches used to clamp together the top shell and bottom shell of a case, and more particularly to latches which have retractable assemblies and handles.
2. Description of the Prior Art
Special cases are now used to transport sensitive equipment such as electronic equipment all over the world. The equipment must be sent through normal freight handling channels and be able to withstand the resulting rough handling. The special cases have features such as recessed ribbing that allow them to absorb shock on impact and elastometric shock mounts that handle any remaining vibrations. The standard case is that of a "clam shell" design and has a top shell and a bottom shell. The case also has a pair of edge extrusions, one of which has a male edge and the other of which has a female edge, which are mounted on the peripheral rims of the top and bottom shells. The case further has a rubber gasket which is adapted to be placed between the male and the female edges of the edge extrusions so that the case may be sealed. The casing hardware includes hinges, locks, handles and latches.
Latches for these cases are the subject of the present invention. There are a variety of different types of toggle latches presently on the market and some designs recognize the need for a safety catch to prevent accidental opening of the latch. This feature is particularly useful in heavy duty areas such as where the latch is used to retain large containers and when the containers are roughly handled.
A common way to maintain the latch in the closed position so that the conventional lever is not accidentally displaced causing the latch to open is to use a wire to retain the opening lever of the toggle assembly to the fixed portion and maintain a positive lock condition. When the lock is to be opened, the wire must be unwound or cut. Unwinding of the wire can be a time consuming procedure both in opening and refastening of the latch. Similarly, if the latch is to be refastened, the cut wire can naturally not be reattached and a new wire has to be used if one is available.
Another problem with current latches is that the latch often protrudes from the case when the latch is open, which can lead to the latch being accidentally sheared off if the protruding latch and some object have a collision. Also, on some latch designs, the handle of the latch can protrude even when the latch is in a closed position. This can lead to the same problem of the handle or the entire latch being accidentally sheared off, when the protruding handle and some object have a collision.
Accordingly, there is a need for a retractable safety latch which is inexpensive to manufacture. Ease of attachment and operation are important factors, particularly when dealing with a mass produced item such as a latch. Examples of several types of fasteners and toggle latches are in U.S. Pat. Nos. 1,329,869, 2,739,003, 2,991,106, 3,181,726, and 4,284,202. Examples of toggle latches with safety catches are in U.S. Pat. Nos. 1,455,625, 3,936,082, and 4,307,906. U.S. Pat. No. 1,455,625 discloses a pin and detent arrangement for holding the latch in place. U.S. Pat. No. 3,936,082 discloses a luggage latch having means for preventing accidental release. U.S. Pat. No. 4,307,906 discloses a latch having a spring 88 used to hold the handle in a closed position. From all of these references, it is clear that a positive locking latch is desirable and necessary. Accordingly, improvements in this area would be extremely valuable and desirable in the field of manufacturing and using cases and trunks. Also, it would be valuable and desirable to have a latch that is sturdier and less complex than designs in the prior art.